Answer:
C. x + 9 = 11
Step-by-step explanation:
We are trying to identify which of the equations does not match with the others. In this case, solve for x in each equation:
Option A):
6 + x = 9
Subtract 6 from both sides:
6 (-6) + x = 9 (-6)
x = 9 - 6
x = 3
Option B):
15 = x + 12
Subtract 12 from both sides:
15 (-12) = x + 12 (-12)
15 - 12 = x
x = 3
Option C):
x + 9 = 11
Subtract 9 from both sides:
x + 9 (-9) = 11 (-9)
x = 11 - 9
x = 2
Option D):
7 + x = 10
Subtract 7 from both sides:
x + 7 (-7) = 10 (-7)
x = 10 - 7
x = 3
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As you can tell, all the equations end with x = 3 as there answers except C. x+9=11, making (C) your answer.
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